The present invention relates to a capacitive touch screen sensor and corresponding method of fabrication.
In capacitive-type touch screen sensors, transparent rows and columns of conductive electrodes are patterned and coupled through a dielectric medium to obtain a matrix of electrodes. In this respect, patterns of transparent conductive materials, such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Silver pattern and the like, are used to form the electrodes. For a quality touch sensor, it is important to achieve high transmittance, high conductivity and low visibility of electrode features.
In a typical patterning process, the conductive material is etched away from a substrate while keeping a desired pattern of conductive material on the substrate to create the matrix of electrodes. After the patterning process, the pattern typically becomes visible to the naked eye. To reduce visibility of the pattern, refractive index of the materials to fabricate the capacitive touch screen sensor may be selected in a way to get lower visibility. However, this method is expensive and requires precise control of material composition, thickness and process control.
It is an object of the present invention to provide a capacitive touch screen sensor and corresponding method of fabrication to address at least one of the problems of the prior art and/or to provide the public with a useful choice.